The ten-year (1993-2002) Baltimore Longitudinal Study of Aging prostate aging and disease study has both retrospective and prospective arms involving repeated assessments of anatomical, physiological, hormonal, and behavioral aspects of age-associated changes in prostate size. A major goal of the study is to identify antecedents of prostate cancer and benign prostatic hyperplasia (BPH). Current research is addressing the question of when serial measures of PSA are necessary, an interesting question because of the current controversy in medical practice about the clinical value of PSA. Recent work has addressed the rate of growth of the prostate using longitudinal assessments by MRI. The overall rate of growth averaged 2.36 cc/year. The growth rate peaked in the 56 to 65 age range with an average growth of 4.15 cc/year, and then declined rapidly for older men. We have also examined whether serum selenium levels correlated with the risk of later development of prostate cancer using a case control design. Cases included 52 men in whom serum selenium was measured an average of 3.83 ? 1.85 years prior to diagnosis. These were compared to 96 age matched controls with no detectable prostatic disease. Serum selenium levels were found to decrease with increasing age. The risk of prostate cancer was lower in men with serum selenium levels above the lowest quartile with odds ratios of .29,.34, and .48 for subsequent quartiles (p=0.049). Age of the patients at diagnosis did not affect the protective effect observed for higher selenium values. The findings are consistent with other reports that higher serum selenium levels may be associated with a decreased risk of prostate cancer. At this point, we cannot address whether supplemental selenium may reduce the risk of prostate cancer. - prostate disease prostate cancer benign prostatic hyperplasia aging longitudinal studies prostate specific antigen - Human Subjects